Systems and methods for electrosurigical treatment of obstructive sleep disorders

Abstract

Systems, apparatus, and methods for selectively applying electrical energy to a target location within the head or neck of a patient for treating obstructive sleep disorders. A method of the present invention involves positioning an electrosurgical probe with respect to a target tissue that affects the aperture of the upper airway of the patient. For example, the position of the tongue and the radix linguae affect the upper airway. The position of the tongue is controlled by the genioglossus muscle and tendon. The tendon of the genioglossus muscle may be irreversibly shrunk by positioning an electrosurgical probe in at least close proximity to the tendon, and applying a suitable high frequency voltage to the probe in a sub-ablation mode. Controlled heating of the tendon is effected by application of the high frequency voltage to the probe, wherein the voltage is insufficient to ablate the tissue of the tendon. The controlled heating of the tendon effects contraction of collagen fibers of the tendon, whereby the tongue is advanced and/or depressed, and the aperture of the upper airway is increased.

What is claimed is:  
     
       1. A method of shrinking a target tissue using an electrosurgical probe, comprising:
 a) positioning a pointed distal end of the electrosurgical probe into the target tissue of a patient, the probe distal end having an electrode assembly, the electrode assembly including at least one active electrode and at least one return electrode; and  
 b) after said step a), applying a high frequency voltage between the at least one active electrode and the at least one return electrode, wherein the target tissue affects the aperture of the upper airway of the patient, wherein the high frequency voltage is insufficient to ablate the target tissue, and wherein the target tissue undergoes controlled thermal heating to a temperature in the range of from about 55° to 75° C. such that at least a portion of the target tissue is irreversibly shrunk, wherein the target tissue comprises a genioglossus tendon.  
 
     
     
       2. The method of  claim 1 , wherein the target tissue includes collagen fibers. 
     
     
       3. The method of  claim 1 , wherein the high frequency voltage is sufficient to contract collagen fibers of the genioglossus tendon. 
     
     
       4. The method of  claim 1 , wherein said step b) causes an electric current to flow through at least a portion of the genioglossus tendon. 
     
     
       5. The method of  claim 1 , wherein the electrosurgical probe is electrically coupled to a high frequency power supply to provide a power supply/probe combination, the power supply/probe combination configured to operate in at least a sub-ablation mode, wherein the sub-ablation mode is adapted for shrinking the target tissue. 
     
     
       6. The method of  claim 5 , wherein the target tissue undergoes controlled thermal heating to a temperature in the range of from about 60° C. to 70° C. 
     
     
       7. The method of  claim 1 , wherein shrinkage of the genioglossus tendons causes at least one of depression of the tongue and advancement of the radix linguae. 
     
     
       8. The method of  claim 1 , wherein the at least one active electrode comprises a plurality of electrically isolated active electrodes. 
     
     
       9. The method of  claim 1 , wherein the electrosurgical probe comprises a shaft having a shaft distal end and an electrically insulating electrode support disposed on the shaft distal end, the at least one active electrode disposed on the electrode support. 
     
     
       10. The method of  claim 9 , wherein the electrode support is arranged laterally on the shaft distal end. 
     
     
       11. The method of  claim 9 , wherein the at least one return electrode comprises an exposed portion of the shaft distal end. 
     
     
       12. The method of  claim 1 , wherein the electrosurgical probe comprises a fluid delivery unit adapted for delivering an electrically conductive fluid to the electrode assembly. 
     
     
       13. A method of  claim 1 , wherein the electrosurgical probe further comprises an aspiration unit adapted for aspirating excess fluid from the shaft distal end. 
     
     
       14. The method of  claim 1 , further comprising:
 c) delivering an electrically conductive fluid between the at least one active electrode and the at least one return electrode, wherein the electrically conductive fluid provides a current flow path between the at least one active electrode and the at least one return electrode, and wherein the high frequency voltage is insufficient to initiate a plasma in the presence of the electrically conductive fluid.  
 
     
     
       15. The method of  claim 1 , further comprising: during said step a), translating the distal end of the electrosurgical probe with respect to the surface of tho genioglossus tendon. 
     
     
       16. The method of  claim 1 , further comprising:
 d) prior to said step a), accessing the genioglossus tendon by forming an incision in the skin of the patient.  
 
     
     
       17. The method of  claim 16 , wherein the incision is formed at a location inferior to the genioglossus tendon. 
     
     
       18. A method of shortening a genioglossus tendon, comprising:
 a) positioning the distal end of an electrosurgical probe in at least close proximity to the genioglossus tendon, the probe including an electrode assembly disposed on the probe distal end, the electrode assembly having at least one active electrode and at least one return electrode, the at least one active electrode disposed on an electrically insulating electrode support; and  
 b) applying a high frequency voltage between the at least one active electrode and the at least one return electrode, wherein the high frequency voltage is insufficient to ablate the genioglossus tendon, and wherein the genioglossus tendon undergoes controlled thermal heating to a temperature in the range of from about 55° C. to 75° C. such that the genioglossus tendon is irreversibly shortened.  
 
     
     
       19. The method of  claim 18 , wherein said step a) comprises positioning the distal end of the electrosurgical probe in at least close proximity to a first location of the genioglossus tendon, and the method further comprises:
 c) after said step b), repositioning the distal end of the electrosurgical probe in at least close proximity to at least a second location of the genioglossus tendon; and  
 d) repeating said step b).  
 
     
     
       20. The method of  claim 18 , wherein said step a) comprises contacting the genioglossus tendon with the at least one active electrode. 
     
     
       21. The method of  claim 18 , wherein said step a) comprises positioning the distal end of the probe such that a gap exists between the active electrode and the genioglossus tendon. 
     
     
       22. The method of  claim 21 , wherein the gap is in the range of from about 0.05 mm to 5 mm. 
     
     
       23. The method of  claim 18 , wherein the at least one return electrode is spaced apart from the at least one active electrode, and the method further comprises:
 e) prior to said step b), delivering an electrically conductive fluid to the electrode assembly, wherein the electrically conductive fluid provides a current flow path between the at least one active electrode and the at least one return electrode, and the electrically conductive fluid is heated by applying the high frequency voltage.  
 
     
     
       24. The method of  claim 23 , wherein applying the high frequency voltage between the at least one active electrode and the at least one return electrode heats the electrically conductive fluid to provide a quantity of heated fluid, wherein the heated fluid elevates the temperature of at least a portion of the genioglossus tendon sufficiently to cause irreversible hydrothermal shrinkage of collagen fibers within the genioglossus tendon. 
     
     
       25. The method of  claim 23 , wherein the electrically conductive fluid comprises isotonic saline. 
     
     
       26. The method of  claim 18 , further comprising:
 f) during said step b), translating the distal end of the electrosurgical probe with respect to the surface of the genioglossus tendon.  
 
     
     
       27. The method of  claim 18 , wherein the high frequency voltage is in the range of from about 20 volts RMS to 90 volts RMS. 
     
     
       28. The method of  claim 18 , wherein said step b) effects controlled heating of at least a portion of the genioglossus tendon to a temperature in the range of from about 60° C. to 70° C. 
     
     
       29. The method of  claim 18 , wherein said step b) effects controlled heating of at least the surface of the genioglossus tendon over a length in the range of from about 0.5 cm to 2.5 cm. 
     
     
       30. The method of  claim 29 , wherein said step b) effects controlled heating of the genioglossus tendon to a depth in the range of from about 0.1 mm to about 5.0 mm. 
     
     
       31. The method of  claim 18 , wherein said step b) effects shortening of the genioglossus tendon by a distance in the range of from about 1 mm to about 5 mm. 
     
     
       32. The method of  claim 18 , wherein shortening of the genioglossus tendon causes the tongue to be advanced or depressed. 
     
     
       33. The method of  claim 32 , wherein advancement of the tongue increases the aperture of the upper airway and allows normal breathing during sleep. 
     
     
       34. A method of treating an obstructive sleep disorder, comprising:
 a) accessing a tendon within the head of a patient;  
 b) positioning the distal end of an electrosurgical probe in at least close proximity to the tendon, the probe including an electrode assembly having at least one active electrode;  
 c) after said step b), applying a high frequency voltage between the at least one active electrode and at least one return electrode, wherein the high frequency voltage effects the thermal heating of at least a portion of the tendon to increase an aperture of the upper airway.  
 
     
     
       35. The method of  claim 34  wherein the at least one return electrode is located on the electrode assembly, the at least one active electrode being disposed on an electrically insulating support, and the electrode assembly is disposed at the probe distal end, the method further comprising providing an electrically conductive fluid at the probe distal end. 
     
     
       36. The method of  claim 34  wherein the tendon is inserted on the mandibular symphyis and attached to the genioglossus muscle. 
     
     
       37. The method of  claim 36  wherein the applying step is carried out by applying a high frequency voltage sufficient to effect the controlled thermal heating of at least a portion of the tendon to increase the aperture of the upper airway to a temperature in the range of from about 60C to 70C such that at least a portion of the tendon is irreversibly shrunk, whereby the tongue or the radix linguae is advanced and the aperture of the upper airway is increased. 
     
     
       38. The method of  claim 34 , wherein the high frequency voltage is insufficient to ablate tissue of the tendon. 
     
     
       39. The method of  claim 34 , further comprising: aspirating excess fluid from the milieu surrounding the tendon. 
     
     
       40. The method of  claim 38 , wherein the probe further includes an aspiration unit, and the excess fluid is aspirated via the aspiration unit. 
     
     
       41. The method of  claim 34 , wherein said step b) comprises sequentially positioning the distal end of the electrosurgical probe in at least close proximity to a plurality of locations of the genioglossus tendon, and wherein the high frequency voltage of said step d) is sequentially applied at each of the plurality of locations of the genioglossus tendon. 
     
     
       42. The method of  claim 35 , wherein the probe includes a fluid delivery unit, and said step c) comprises delivering an electrically conductive fluid to the electrode assembly via the fluid delivery unit. 
     
     
       43. The method of  claim 42 , wherein said step c) provides a current flow path between the at least one active electrode and the at least one return electrode. 
     
     
       44. The method of  claim 35 , wherein the electrically conductive fluid comprises isotonic saline. 
     
     
       45. The method of  claim 34 , wherein the probe further includes a shaft having a shaft distal end and a shaft proximal end, a handle affixed to the shaft proximal end, and a connection block housed within the handle, the connection block adapted for electrically coupling the electrode assembly to a high frequency power supply, the high frequency power supply adapted for operating in at least a sub-ablation mode, and wherein the electrode assembly is disposed on the shaft distal end. 
     
     
       46. The method of  claim 34 , wherein the at least one active electrode is arranged at an angle with respect to the longitudinal axis of the shaft, wherein the angle is in the range of from about 35° to 145°. 
     
     
       47. The method of  claim 34 , wherein the distal end of the electrosurgical probe has dimensions adapted for accessing the genioglossus tendon. 
     
     
       48. The method of  claim 34 , wherein said step a) comprises forming an incision in the skin of the patient. 
     
     
       49. The method of  claim 48 , wherein the incision is formed under the chin of the patient. 
     
     
       50. The method of  claim 48 , wherein the incision is formed electrosurgically using a second electrosurgical instrument. 
     
     
       51. The method of  claim 48 , wherein the incision is formed by localized volumetric removal of skin tissue. 
     
     
       52. A method of treating an obstructive sleep disorder, comprising:
 a) accessing the genioglossus tendon; and  
 b) applying thermal energy to at least a portion of the genioglossus tendon to increase an aperture of the upper airway.  
 
     
     
       53. The method of  claim 52  wherein the applying thermal energy step comprises heating the genioglossus tendon sufficiently to cause shrinkage of collagen fibers within the genioglossus tendon. 
     
     
       54. The method of  claim 52  wherein the applying thermal energy step comprises applying high frequency electrical energy to at least a portion of the genioglossus tendon.